1. Field of the Invention
This invention relates to .alpha.,.omega.- chloro terminated polysilane capable of accepting any desired functional group and useful as a source material for forming copolymers with other polymers.
2. Prior Art
Most industrial processes for preparing polysilanes utilize coupling reaction of dihalogenosilanes with alkali metals as reported in Journal of Polymer Science: Polymer Chemistry Edition, Vol. 22, 159-170 (1984) and Journal of Organometallic Chemistry, Vol. 300, 327 (1986). These processes produce polysilanes in the form of mixtures of cyclic polymers and halo- or hydrogen- terminated polymers. It is difficult to quantitatively obtain terminally modified polymers from these mixtures.
With respect to the synthesis of single end modified polysilanes, Sakurai et al. attempted living polymerization from polymers containing a disilane unit for introducing hydrogen or carboxylic acid as well as copolymerization of such polymers with polymethyl methacrylate (PMMA) as reported in Kagaku to Kogyo (Chemistry & Industry), Vol. 42, No. 4, 744. This attempt, however, has several industrial problems including limited type of substituents and limited availability of monomers.
Exemplary synthesis of both and single end reactive polysilanes is reported in Journal of Organometallic Chemistry, Vol. 2, 478-484 (1964) and Journal of Organometallic Chemistry, Vol. 23, 63-69 (1970). More specifically, chloro-terminated oligosilanes can be prepared by reacting permethyloligosilanes with acetyl chloride in the presence of aluminum chloride. Also chloro-terminated oligosilanes can be prepared by reacting phenyl-terminated oligo silanes with hydrogen chloride or chlorosilane in the presence of aluminum chloride. These chloro-terminated oligosilanes, however, have a low polymerization degree.